A powerful earthquake struck Nepal on Saturday, killing hundreds across four countries as the violently shaking earth collapsed houses, levelled centuries-old temples and triggered avalanches on Mount Everest.
'Great earthquake', but is this the big one?
The massive 7.9-magnitude earthquake that killed hundreds of people on Saturday as it jolted large swathes of Nepal and northern India was the strongest to hit the region in 81 years. But was it the "big one" that experts have been talking about for some time?
Why did it happen?
The area has a history of earthquakes, with a 6.8-magnitude quake that hit eastern Nepal in August 1988 killing 721 people. Another 8.1- magnitude quake killed 10,700 people in Nepal and eastern India in 1934.
1934 :: Earthquake in Bihar and Nepal .With 8.0 Magnitude, epicenter was located in Eastern Nepal Near Mount Everest pic.twitter.com/2s3utzfmCU— indianhistorypics (@IndiaHistorypic) April 25, 2015
And less than two months before Saturday's quake, a team of Indian scientists predicted in a study that a "great earthquake" was due in the Himalayan region.
The "frontal thrust in central Himalaya may have remained seismically inactive during the past 700 years. Considering this long elapsed time, a great earthquake may be due in the region," the scientists wrote in the study published in the Journal of Geophysical Research: Solid Earth.
More quakes in store
CP Rajendran, senior associate at the Jawaharlal Nehru Centre for Advanced Scientific Research in Bengaluru, told Hindustan Times: "The earth has probably released part of the accumulated strain. More such earthquakes could be generated in the future along this active plate boundary."
Experts pointed out that Saturday's quake was shallow, intensifying the amount of energy released over a relatively small area. While the tremor was massive, the 'big one' could still be in store.
Saturday's temblor can be classified as a 'great earthquake' and its aftershocks will continue for next 10 to 15 days, according to RK Chadha, the chief scientist at the CSIR's National Geophysical Research Institute.
As far back as 2012, the United States Agency for International Development too had warned of the impact of a massive quake in Nepal.
In an article, the agency stated: "…for the 28 million people of Nepal, the risk of earthquakes is what looms largest, in particular, the proverbial 'big one'- an earthquake impacting urban areas that would eclipse those of recent memory…there is concern among seismologists that the city (Kathmandu) could be struck by an earthquake of magnitude 8.0 or greater."
How to track earthquakes and keep away from danger?
The US Geological Survey's tracking website, earthquake.usgs.gov, is a fast and reliable repository of information about earthquakes. There are also a few mobile apps that can be used. 'Earthquake Alert' and 'Earthquake' are two reliable applications that use data from the USGS website.
World's strongest earthquakes
*Chile, 1960 - a 9.5-magnitude quake triggered a tsunami. At least 1,700 people killed.
*Alaska, 1964 - 131 people killed by a 9.2 earthquake.
*Indonesia, 2004 - the devastating 9.1 earthquake and ensuing tsunami killed more than 230,000 people in a dozen countries.
*Japan, 2011 - a 9.0 quake triggered a tsunami, killing more than 18,000 people.
*Russia, 1952 - another 9.0 earthquake caused damage but no casualties were reported.